RE: Multi cabinet control panel routing

> Honestly at this point I don't care about cost so much. I am looking
> for an
> elegant solution to this problem and this is pretty nice (I think :)
>
I hear you there! I'm forever trapped in "must save pennies to make
margin" mode for work though... ;-)

> >Drop me an e-mail with what you're having trouble with and I'll try
> to
> >help...
>
> A lot of my problem was just understanding how to tell it what I was
> doing.
> The bread board version uses a mess of OC output AND gates 1 pin on
> each
> gate is the input line from the control panel the other side is the
> "enable"
> from the 3->8 selector. I just don't see a chip library with 74
> series
> parts to drop in..... This is where my ignorance with the tool really
> comes
> into play.
>
Yeah, the lack of 74xx type functions in Synario had me pretty baffled
for a while there too. You can either build them yourself from raw
gates (which I did for most of my stuff), or model them in ABEL. The
main "gotcha" is that the concept of an OC or tri-state doesn't really
exist inside the programmable chips. You have to kinda re-think the
design to fit the architecture. (That's what took the longest when
trying to adapt the TTL implementations of the Pacman daughtercards --
you can't just have registers hanging on the same wire that are
tri-stated when not active.)

> >> If someone can help me I would be glad to contribute to there new
> >> years beer
> v> fund :) This is the last part I need to solve to complete a
> project I
> >> have
> >> been working on for nearly 3 years.
> >>
> >I still think a cheap little microcontroller would be best though.
> >(What are your main requirements? I/O count?)
>
> Primary requirement
> 20 bit in
> 20 bit out
> 3 bits of mode selection.
>
Well, I think Zonn's on the right track. I'd look at something like the
Atmel AT90S4414 uController and read the inputs as a matrix. The 4414
has 32 lines of IO, built-in flash and SRAM, etc. Use one port to scan
your "inputs" as a switch matrix, and then use 20 dedicated output lines
for you parallel presentation to the game interface. The AVR (Atmel)
ports will sink 20mA each. (Not like a PC keyboard uses 105 lines of
I/O. I bet you there's a PIC appnote somewhere that shows how to read a
switch matrix with just a few IO lines...)

The Atmel development kit with a circuitboard/programmer and software
(assembler, programmer, simulator) is only $49. At the AT90S4414 in
singles is only about $6.75 (sub $5 in 100's from distribution). And
you can just program it in assembly, or IAR has a demo version of their
C compiler you can use for free for up to 256 bytes of object code (or
something like that)...

-Clay
Received on Wed Dec 2 19:18:33 1998